In this proposal we provide a rationale for continued infrastructure support for the Singapore Chinese Health Study that enrolled 63,257 Chinese men and women at baseline in the early 1990s in Singapore. Infrastructure support is needed to maintain and enhance the established infrastructure for this unique cancer epidemiology cohort with repeated collections of questionnaire survey data and biological samples from cohort participants. To date, approximately 20% of the cohort participants were diagnosed with cancers; more than 5,500 cancer patients provided baseline biological samples collected before cancer diagnosis. In the next 5 years the Singapore Chinese Health Study will accrue an additional 4,000 new cancer cases, 2,000 of them with available baseline biospecimens that will provide unique resources for development of biomarker-based cancer epidemiological studies. With the completion of the genome-wide genotyping on the entire cohort and exosome gene sequence in the next two years, this cancer epidemiology cohort will also provide unique opportunity for examining the gene-environmental interaction on risk of cancer. Some of the novel findings from this Asian population has provided a strong rationale for us to conduct chemoprevention trials in U.S. populations. Leveraging the unique and advanced system of electronic medical records and disease registries, we have virtually full retention of the participants; only less than 0.1% of the original cohort participants were known to be lost to our monitoring and tracking cancer incidence, cancer mortality, and many other chronic diseases due to their migration out of Singapore. During the next 5-year study period, we propose to: (1) continue to follow up for all surviving participants for cancer incidence, cancer mortality, cause-specific death, and other non-cancer health outcomes; (2) maintain and update the biorepositories; (3) update and integrate all data elements from follow-up interviews, assessment of disease outcomes, dynamic biorepository inventories, and new laboratory measurements into the master cohort database for research projects; and (4) support and enhance innovative cancer epidemiological studies as cohort-specific ancillary projects and large cohort consortium projects. We anticipate that the established resources of this Asian cohort will become even more scientifically valuable over the next five years as the young participants, especially those who provided baseline biological samples, will enter into the age of maximal cancer incidence, thereby increasing the number of cancer cases that provide resources for pre-disease biomarker-based research projects.